When continuous image data are to be recorded or reproduced by a disc device that records video signals in a DV (Digital Video) format on a disc, or reproduces video signals in the DV format from the disc, the data are recorded/reproduced on/from the disc surface, from an outer radius toward an inner radius or from an inner radius toward an outer radius, in the order of LBA (Logical Block Address), while changing heads and discs.
At this time, a rotational delay resulting from overhead of commands or caused by retry due to an error sometimes occurs at the recording or reproduction, and thus the recording or reproduction may take much time. In such case, when consecutive DV signals are to be recorded or reproduced, and the recording or reproduction cannot be performed within 33.34 mS corresponding to a recording or reproduction time of one frame, this frame cannot be recorded or reproduced, thereby resulting in frame dropping.
To overcome this problem, there are “An information recording/reproducing apparatus and an information recording/reproducing method”, which have been already disclosed in Japanese Published Patent Application No. 2000-350139.
FIG. 1 is a block diagram illustrating an information recording/reproducing apparatus, and FIG. 2 is a diagram showing a frame memory configuration of the information recording/reproducing apparatus. FIGS. 8 to 11 are flowcharts showing recording methods in conventional information recording/reproducing methods. FIG. 12 are diagrams showing execution times in cases where signals are recorded on a disc surface by the conventional information recording/reproducing method.
Here, in FIG. 12, the units of recording that have already been recorded are shown by negative numbers, and when the unit of recording is divided at the recording, the divided units are shown by numbers with subscripts such as 1-1 or 1-2.
As shown in FIG. 1, this conventional information recording/reproducing apparatus comprises a 1394 interface 1 that receives a serial signal from a DV device 7 and converts the signal into a parallel signal; a disc controller 2 that temporarily stores the parallel signal into a frame memory 6 to control the flow of the signal, and modulates or demodulates the DV signal to be recorded/reproduced on/from a disc 4 (information recording medium); a recording/reproducing circuit 3 that records the DV signal on the disc 4 or reproduces the DV signal from the disc 4; and a CPU 5 that controls the disc controller 2. When a DV signal that is inputted from the DV device 7 and received through the 1394 interface 1 is to be recorded on the disc 4, the DV serial signal is once converted into a parallel signal by the 1394 interface 1. Thereafter, one frame (235 sectors) of data to be recorded are stored in the frame memory 6 by the disk controller 2 in a format in which a sector number is assigned to each sector, as shown in FIG. 2 that is a diagram illustrating a frame memory configuration of the conventional information recording/reproducing apparatus. The stored data to be recorded are modulated by the disc controller 2, and then recorded on the disc 4 by the recording/reproducing circuit 3.
At this time, according to the information recording/reproducing method of Prior Art 1 as shown by a flowchart of FIG. 8 that illustrates a DV signal recording method in a conventional information recording/reproducing method, when the DV signal is to be recorded on a disc (information recording/reproducing carrier), the data to be recorded are temporarily stored in the memory (step S1), and a LBA(S) as a recording start LBA is set (step S2). Then, the number of frames to be recorded (Frame(R)) is set (step S3). Thereafter, when the recording is to be performed, initially from a position on the disc at which a command is issued and the recording is permitted (steps S12 to S14), recording of data corresponding to LBA of this position is performed (steps S5 to S6), and then data that have not been recorded are recorded thereafter at LBAs on the disc corresponding to the data (steps S7 to S8). These processes are repeated until the number of recorded frames reaches the set number of frames to be recorded (steps S9 to S11), whereby an increase in the recording execution time resulting from the rotational delay, which is caused by the command overhead at the recording of DV signals can be avoided.
Further, according to an information recording/reproducing method of Prior Art 2 as shown by a flowchart of FIG. 9 that illustrates a DV signal recording method of the conventional information recording/reproducing method, when a DV signal is to be recorded on a disc (information recording medium), the data to be recorded are temporarily stored in a memory (step S1), and a LBA(S) as a recording start LBA is set (step S2). Then, the number of frames (Frame(R)) to be recorded is set (step S3). Thereafter, when recording is to be performed, a LBA for starting data recording is previously set at a larger value than a LBA at which a command is issued and recording is permitted (step S4), then from a position on the disc corresponding to the LBA at which the command is issued and the recording is started, recording of data corresponding to the LBA is performed (steps S5 to S6), and data that have not been recorded are recorded thereafter at LBAs on the disc corresponding to the data (steps S7 to S8). These processes are repeated until the number of recorded frames reaches the set number of frames to be recorded (steps S9 to S11). Accordingly, an apparatus and a method for detecting a LBA at which a command is issued and the recording is permitted are dispensed with, whereby rotational delay that is caused by command overhead can be eliminated with a simpler configuration.
On the other hand, an information recording/reproducing method of Prior Art 3 as shown by a flowchart of FIG. 10 that illustrates a data recording method of a conventional information recording/reproducing method can reduce a recording execution time also in cases where the type of a signal to be recorded is different from the DV signal, and the number of sectors in the signal to be recorded is different from that of the DV signal in the information recording/reproducing method of Prior Art 1 as shown in FIG. 8 (step S15).
Further, an information recording/reproducing method of Prior Art 4 as shown by a flowchart of FIG. 11 that illustrates a data recording method of a conventional information recording/reproducing method can reduce recording execution time also in cases where the type of a signal to be recorded is different from the DV signal and the number of sectors in the signal to be recorded is different from that of the DV signal in the information recording/reproducing method of Prior Art 2 as shown in FIG. 9 (step S15).
However, as in the above-mentioned information recording/reproducing method of Prior Art 1 or 3, when from a position on the disc at which a command is issued and recording or reproduction is permitted, recording or reproduction of data corresponding to a LBA of that position is performed, and then data that have not been recorded or reproduced are recorded or reproduced thereafter at LBAs on the disc corresponding to the data, there are cases where one rotational delay occurs after data stored in the frame memory is recorded without being divided, as shown by Prior Art 1 of FIG. 12(a) or Prior Art 3 of FIG. 12(c) (after the recording unit 2 or 4), and optimization of the recording time cannot be sufficiently performed.
In addition, as in the above-mentioned information recording/reproducing method of Prior Art 2 or 4, when a LBA for starting recording or reproduction of data is previously set at a larger value than a LBA at which a command is issued and the recording or reproduction is permitted, then from a position on the disc corresponding to a LBA at which a command is issued and the recording or reproduction is started, recording or reproduction of data corresponding to the LBA is performed, and then data that have not been recorded or reproduced are thereafter recorded or reproduced on/from LBAs on the disc corresponding to the data, the data stored in the memory is always divided to be recorded as shown in Prior Art 2 of FIG. 12(b) or Prior Art 4 of FIG. 12(d). Accordingly, this method is less effective for reduction in the recording time in cases where continuous recording or reproduction is performed.
The present invention is made to solve the above-mentioned problems, and has for its object to provide an information recording/reproducing method that avoids an increase in recording/reproduction execution time resulting from a rotational delay, and reduces recording/reproduction time to optimize the recording/reproduction execution time.